Triggering Exothermic Water Dissociation on Copper via Rhenium Implantation for Enhanced Alkaline Hydrogen Generation

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Copper (Cu) is a cost-effective material for energy conversion but struggles with high water dissociation energy barriers in alkaline hydrogen evolution reactions (HER).
• Foreign element incorporation can modulate electronic properties and enhance catalytic activity.

Purpose of the Study:

• To enhance the electrocatalytic performance of copper for alkaline HER by incorporating rhenium (Re).
• To develop a scalable strategy for creating platinum group element-free electrocatalysts.

Main Methods:

• Co-electrodeposition of rhenium into a copper lattice.
• Electrochemical characterization including overpotential measurements, stability tests, electrochemical impedance spectroscopy (EIS), electrochemical surface area (ECSA), and turnover frequency (TOF) analysis.
• In situ Raman spectroscopy and density functional theory (DFT) studies.

Main Results:

• The optimized CuRe-10/CP catalyst achieved an overpotential of 46 mV at 10 mA cm⁻² and demonstrated stability for 450 hours at 50 mA cm⁻² in 1.0 M KOH.
• Re incorporation promoted exothermic water dissociation and enhanced water adsorption, significantly improving catalytic activity.
• The catalyst exhibited exceptional activity and stability in simulated and alkaline seawater.

Conclusions:

• Rhenium incorporation into copper significantly enhances electrocatalytic activity and stability for alkaline HER.
• The study presents a scalable method for designing efficient, low-cost electrocatalysts for hydrogen production.
• This approach offers a viable alternative to platinum group metals in energy conversion applications.